2-p-nitrobenzamidoacetohydroxamic acid

ABSTRACT

NOVEL BENZAMIDOCETOHYDROXAMIC ACIDS OF THE FORMULA:   1-(HO-NH-CO-CH2-NH-CO-),4-R-BENZENE   WHEREIN R IS NITRO OR CHLORO ARE POTENT INHIBITORS OF UREASE. COMBINED WITH URINARY TRACT ANTIBACTERIALS AN IMPROVEMENT IN THE PREVENTION OF FORMATION OF URINARY CALCULI IN THE PRESENCE OF UREA SPLITTING ORGANISMS IS OBSERVED.

U.S. Cl. 260--500.5 H

United States Patent Office 3,804,888 Z-p-NITROBENZAMIADOgCETOHYDROXAMIC Roland N. Johnson and Jon A. Andersen, Norwich, N.Y., assignors to Morton-Norwich Products, Inc., Norwich,

No Drawing. Original application May 17, 1971, Ser. No. 144,322, now Patent No. 3,728,380. Divided and this application Sept. 25, 1972, Ser. No. 291,524

Int. Cl. A61k 27/00; C07c 103/30 1 Claim ABSTRACT OF THE DISCLOSURE Novel benzamidoacetohydroxamic acids of the formula:

R- CONHOHzCONHOH wherein R is nitro or chloro are potent inhibitors of urease. Combined with urinary tract antibacterials an improvement in the prevention of formation of urinary calculi in the presence of urea splitting organisms is observed.

CONHCHQCONHOH (I) wherein R is nitro or chloro and their combination with urinary tract anti-bacterial agents.

The compounds of FormulaI are potent urease inhibitors. They may be readily prepared according to this scheme:

R-QCONHOHzCOOOaH: Hmon R-Q-C ounornoonnon CaNsOH wherein R is nitro or chloro. Exemplary of this scheme are the following. EXAMPLE I Z-(p-nitrobenzamido)acetohydroxamic acid A solution of hydroxylamine hydrochloride (28 g., 0.4 mole) in methanol (145 ml.) was treated with a solution of KOH (37 g., 0.7 mole) in methanol (84 ml.). The resulting inorganic salt was removed and the filtrate treated with ethyl p-nitrohippurate (84 g., 0.3 mole). After stirring for 3 hours, a solid precipitated. The entire reaction mass was stirred in approximately 500 ml. of water. A white crystalline solid was separated by filtration and dried at 60 to 35 g. The filtrate was acidified with glacial acetic acid to pH 6, precipitating a white crystalline solid which was dried at 60 to 38 g. The two crops were combined with 15 g. from a similar run and recrystallized from methanol to give 69 g. (67%), M.P. 160-1.

Calcd. for C H,N (percent): C, 45.19; H, 3.79; N, 17.57. Found (percent): C, 45.10; H, 3.80; N, 17.53.

EXAMPLE 2 2- (p-chlorobenzamido acetohydroxamic acid Into a suspension of 209 g. (1.50 moles) of glycine ethyl ester hydrochloride in 1200 ml. of dry benzene was slowly added 263 g. (1.50 moles) of p-chlorobenzoylchloride. This mixture was heated under reflux for 22 hours, then filtered and the white precipitate was recrystallized from methanol giving 292 g. (82.5%) of ethyl 2-(p-chlorobenzamido)acetate, M.P. 114-117 C.

3,804,888 Patented Apr. 16, 1974 Analysis.--Calcd. for C H NO Cl (241.67) (percent): C, 54.67; H, 5.01; N, 5.80. Found (percent): C, 54.95; H, 4.97; N, 6.08.

To a stirred solution of 5 8 g. (0.83 mole) of hydroxylamine hydrochloride in 350 ml. of anhydrous methanol was added a solution of g. of potassium hydroxide in ml. of anhydrous methanol. A white salt immediately precipitated. This mixture was cooled in an ice bath and the salt was removed by filtration. The filtrate was placed into a 2 l. flask equipped with a stirrer, a thermometer and a drying tube. To the filtrate was added with stirring 100 g. (0.42 mole) of ethyl 2-(p-chlorobenzamido) acetate which went into solution. Approximately 2 minutes later a thick white precipitate formed. The mixture was stirred at room temperature overnight. The potassium salt was collected by filtration and dried at 60 to 90 g.

A second run of the same size was made with 91 g. of the potassium salt being obtained. The two crops of salt were combined making a total of 181 g. which was placed in 2000 ml. of cold water. Glacial acetic acid (40 ml.) was added to give a final pH of 5. The white precipitate was collected by filtration and dried to g. in a 60 oven. The 160 g. of crude product was recrystallized from 4800 ml. of methanol. After cooling the solution overnight in the refrigerator, the product precipitated as white crystals which were collected by filtration and dried at 60 C. to 121 g. (63.8% overall yield), M.P.

The anti-urease activity of the compounds of this invention is exemplified below.

TABLE I The inhibition 01 urease purified from Proteus mirabili (Pr-91) and of ureiise contained within intact cells 01 several species and strains 01 pro eus Concentration of inhibitor for 50% inhibition The compounds of this invention are valuable adjuncts in the therapy of urinary tract infection caused by urea splitting bacteria such as Proteus mirabilis whereby urea is decomposed to ammonia with resultant formation of insoluble salts such as ammonium magnesium phosphate giving rise to calculi formation and obstruction posing a site of reinfection impairing the efiicacy of otherwise etfective urinary tract antibacterials such as ampicillin, sulfamethoxazole and nitrofurantoin.

When the compounds of this invention are administered in conjunction with known antibacterial agents to rats in which a Proteus mirabilis genitourinary tract infection has been induced, the appearance of calculi is diminished and sometimes prevented. Also, at times, dissolution of formed calculi is accomplished through this joint therapy.

The following table is illustrative of the beneficial result achieved through the concomitant therapy referred to above.

TABLE II Calculi in rats after 7 days infection with Proteus mtrabilts (Pr-91) [Compounds or combinations oi compounds were administered t.i.d. at the indicated dosages tor 6 days hegluing 24 hours after infection] 1gnitlatlstical s cance Mean mg. the difierence phosbetween an Test for potentiation Rats phorus as experimental Dosage, per calculi per and the Compound(s) mg./kg. group bladder control group EU AB None None 50 5. 4 Sultamethoxazole. 12. 1. 9 01 Ampicillin 12.5 9 1 1 05 Nitroiurantoin 2. 5 9 2 2 02 Compound of Example 25 10 3 3 02 Do 60 9 1 0 01 Coumpound of Example 2. 25 8 3 3 05 Do 50 7 2 3 02 cor npound of Example 1 50 p us Suliaxnethoxazole 12. 5 9 0 3 01 01 01 Compound oi Example 25 p us Suliamethoxazole 12. 5 9 0. 6 01 01 01 Corlnpound of Example 50 p us Suliamethoxazole. 12.5 9 0 9 01 01 01 Coz npound of Example 2 25 p us Buliamethoxazole 12.5 9 0 9 01 01 01 Compound 01 Example 1 50 us N itroiurantoin 2. 5 10 0- 3 01 01 01 Compound oi Example 1 25 W Y us Nitr01urantoin-...-.. 2. 5 l0 1 2 01 10 10 corlnpound of Example 2 50 p us Nitroiurantoln 2. 5 9 0. 1 01 01 01 Corlnpound of Example 2 25 p us Nitroiurantoin 2. 5 10 0. 8 01 01 0i Corlnpound of Example 1 50 p us Ampicillin 12.5 10 0 1 01 0i 01 Ooi npound 01 Example 1 25 r p us Ampiclllinut 12. 5 0. 2 10 10 10 corlnpound of Example 2 50 r p us Ampicillin 12.5 9 0. 1 10 01 01 Compound 01 Example 2 plus Ampioillin 1 Statistical evaluation was by the Wilcoxon rank sum test [Wilcoxon et al. "Some Rapid Approximate Statistical Procedures," Lederle Laboratories, 7-9 (1964)] I The number is the probability that the difierence in the mean mg. phosphorus as cystic calculi between rats receiving an antibacterial agent (AB) only or an urease inhibitor (E U) only on the one hand, and the mean mg. phosphorus as cystic calculi from rats receiving both (AB) and (E U) on the other, is a chance occurrence.

The compounds of this invention by themselves and in References Cited conjunction with ampicillin, sulfamethoxazole or nitro- UNITED STATES PATENTS furantoin are readily formulated in pharmaceutical ,5 1/ 1972 Yates et a1. 260-5005 H dosage forms such as tablets, lozenges, suspensions, Zg Z fi LII: troches, and capsules using conventional pharmaceutical 2,279,973 4/1942 Dietrich 260-5005 H carriers and excipients with which there is no incom- FOREIGN PATENTS patibility. 1,048,936 11/1966 Great Britain 260-5005 H What is claimed is:

1. The compound 2-(p-nitrobenzamido)acetohydroxamic acid.

JOSEPH E. EVANS, Primary Examinary US. Cl. X.R. 

